Writing instrument



Aug. 5, 1958 J. uPlc, JR, ET AL ,8

WRITING INSTRUMENT Filed Feb. 9, 1956 FIGI.

a yr Z wz P 5 w -ll'l'llll llllllli illlill 'WRITING INSTRUMENT Joseph Lipic, Jr., Sappington, and Emil J. Lipic, St. Louis, Mo.

This inventionrelates to writing instruments of the character of ball-point pens having retractable nibs. The invention will be described as applied to such a pen. However, it is to be understood that the invention has application to the retractable points of other writing instruments such, for example, as retractable lead pencils or so-c'alled liquid-lead pencils.

Ball-point pens and similar writing instruments consist essentially of a long, ink-filled cartridge closed at one end by a ball mounted in a relatively thin tube which projects from the cartridge, the ball and tube constituting the nib of the pen. The cartridge is mounted in a barrel or housing proportioned to fit the hand of the user. In order to protect the nib of the pen from damage and to protect the pocket of the user from being stained when the pen is clipped to a pocket, the nib of the pen is made retractable into the housing. .This is accomplished by spring manufacture, and simple to operate. It also has certain faults. Because the lug extends through the cross slot .at right angles to the axis of the barrel, if one attempts to put the pen in his pocket without retracting the nib, he is likely to tear his pocket on the projection. The strength of the hairpin spring and of the clip have to be balanced with considerable nicety. If the clip spring is too strong, the lug of the hairpin spring cannot move out against it. If the clip is too weak, it will not effectively perform its function as a clip. The danger of accidental retraction is great, since pressure anywhere along the clip is likely to depress the lug and permit the nib to retract. The provision of the small shoulders has tended to make the operation of the catch difficult, because the shoulders, extending at right angles to the axis of the stem slot and frequently having burrs or sharp edges, tend to dig into the inside surface of the barrel. The T-slot and shoulders must be made to close tolerances. The fact that the lug is bent out from the end of a leg of the hairpin spring at right angles to the axis of the leg makes the lug liable to be bent toward its original position if pres: sure is put on the nib.

One of the objects of this invention is to provide a catch for a writing instrument, which is simple and cheap to manufacture, which is so arranged as to ensure against its being clipped to the pocket while the nib is in extend ed position, which eliminates the likelihood of tearing of biasing the nib and cartridge away from the opening A through which the nib extends in its operative position and by providing a releasable catch to hold the nib in its extended position against the bias of the spring. This invention relates particularly to the catch mechanism.

A catch mechanism which has been used heretofore has a plunger which projects from the end of the barrel opposite the nib. The plunger is provided with a cupshaped recess which receives the closed end of a hairpin type spring. The legs of the hairpin type spring bear against diametrically opposite parts of the inside surface of the/wall of the barrel. The free end of one of the legs is bent outwardly at right angles to form a small lug. The lug is cut out to form a pair of shoulders and a projection between the shoulders. The projection ex tends through a T-slot, the stem of which extends axially of the barrel beneath the pocket clip mounted on the outside of the barrel and the cross slot of which is positinned directly under the pocket-engaging nu-b of the clip. The cross slot is slightly larger than the lug. The stem is slightly wider than the projection but narrower than thelug, so that the shoulders ride on the inside surface of the barrel along the stem section of the slot while the projection extends through it as a guide. In the operation of this prior art device, assuming that the nib 'is inits retracted position, the plunger extends from the barrel and the projection of the catch spring extends through the stem slot. When the plunger is pushed down to move the cartridge against the bias of the'spring, the lug rides down'the stem of the slot until it reaches the cross slot into which it is forced by the resilience of the hairpin spring. When the lug moves into the cross slot it lifts the nub of the clip. In order to restore the nib of the pen to its retracted position, it is only necessary to push down on the clip, forcing the shoulders of the lug below the level of the cross slot, in which position the cartridgebiasing spring will force the cartridge and plunger toward the plunger end of the barrel with the shoulders .of the lug riding onthe inside surface of the barrel along the stem of the slot.

This construction has several virtues. It ischeap to the pocket, which is stronger, easier to operate, less prone to accidental retraction, and simpler to manufacture than catches known heretofore, which permits the use of any strength or construction of clip, does not weaken the clip, and requires less precise slotting of the barrel than-clips known heretofore. Other objects will become apparent to those skilled in the art in the light of the following description and accompanying drawing.

In accordance with this invention, generally stated, a

writing instrument with a retractable nib is provided with a catch having a latch member which projects, when the nib is in its extended position, through the housing of the instrument in such a position with respect to a pocket clip mounted on the exterior of the housing as to cause the nib to retract when one attempts to clip the instrument to, a pocket while the nib is in extended position. The latch is guarded by the nub of the clip, to minimize the chance of accidental retraction. The latch is positioned in such a way that it in no way interferes with'the operation of the clip, which may be made in any desired form or of any desired strength.

In the drawing,

Figure 1 is a view in side elevation of a ball-point pen equipped with a catch constructed in accordance with one embodiment of this invention;

Figure 2 is a view in front elevation of the pen shown in Figure 1;

Figure 3 is an enlarged sectional view taken along the line 33 of Figure 2;

Figure 4 is a fragmentary sectional view corresponding to the view shown in Figure 3 but showing the catch mechanism in the retracted position; and

Figure 5 is a fragmentary view in perspective of the latch leg of the catch mechanism of Figures 14.

Referring now to the drawing, reference numeral 1 indicates a ball-point pen provided with a catch mechanism 2 constructed in accordance with one illustrative embodiment of this invention.

The ball-point pen 1 is provided with the usual inkfilled cartridge 3, having at one end a relatively thin tube 4 in the free end of which a ball 5 is mounted. The ball 5 and tube 4 constitute the nib of the pen. A helical spring 6 is mounted on the cartridge 3 with one end of the spring 6 bearing against a shoulder formed by flattening the cartridge 3 as shown at 7 and the other end of 3 the spring bearing against an internal, annular shoulder 8 of a lower half or nib section 9 of a barrel or housing 10.

The nib section 9 of the barrel 10 is conventional. It is provided with-a restricted passage 12 through-which the tube 4 projects-when the-nib is in extended position, and in whichth'e lower end of the cartridge 3 is journaled. Theupper end of the nib section 9 is-internally threaded as indicated: at 14 and is screwed; oi1 t o an externally threaded end 16 of a bearing plug 20. The bearing plug 20.has a splined or knurledlhead 22 which is force fitted intoan upper half .or clip section 25 of the barrel 10. t The bearing plug is provided with a central; axially-extending passage 23, in which the cartridge 3' is slideably journaled.

A- pocket clip 30 is secured at its upper end 31 to the clip section25. At its, lower end, the clip 30 is provided with a nub 32 which bears/against a solid bridge section 40 of the clip section The bridge section 40 lies-between a latch slot 42 and a guide slot 44 through the Wall of the clip section 25. The guide slot 44 ex tends axially of the barrel 10, immediately beneath the clip between-the nub 32 and the secured end 31 of the clip. The latch slot 42 is aligned axially with the guide slot 44, and extends from a point immediately adjacent the nub 32 toward the nib end of the barrel. A plunger hole 46 in the end of the clip section 25 slideably receives a stem 50 of a plunger 52. The plunger 52 is stepped to provide an annular plunger shoulder 54 which bears against the inside surface of the clip section 25 when the nib of the pen is in its retracted position, as shown in Figure 4. In an enlarged lower section 55 of the plunger 52, is a cup-shaped, recess 56 in which is mounted a closed loop end 60 of a hairpin spring 62.

The hairpin spring 62 has abearing, leg 65 and a latch leg 70. Both the bearing leg 65 and the latch leg 70 are formed with a dog leg 66 immediately adjacent the mouth of the cup 56 of the plunger 52, so asto position thelegs 65 and 70 nearly parallel to and closely adjacent the wall of the clip section 25:01? the barrel 10. Near its free end, the bearing leg 65 is provided with a bearing pad 67. In the embodiment shown, the bearing pad 67 is simply an outwardly pressed dimple which provides a smooth bearing surface against the wall of the clip section.

At its free'end, the latch leg 70 is provided with a latch- 72. Intermediate the latch 72 and the dog leg 66 the latch leg 70 is provided with a guide 74. Both the latch 72 and the guide 74 are integral lateral extensions of the latch leg '70 which have been bent up at right angles to their original position, so that their lines of bending run axially of the leg 70 and of the barrel 10. The guide 74 is so positioned with respect to the guide slot 44 as to extend Within the slot 44 through the full travel of the plunger 52, as shown in Figures 3 and 4. The latch 72 is so positioned with respect to the latch slot 42 as to project through the latchslot 42 when the nib of the pen is in its extended position, but to bear against the inside surface of the bridge when the nib is in its retracted position. The latch 72 is rounded on top to form a cam surface 75. The cam surface 75 ensures smooth and easy operation of the catch and, incooperation with the nub 32, the automatic retraction of the nib when the pen is sought to be clipped to a pocket while the nib is extended. On the clip side, the latch is provided with a straight latch shoulder 73.

In assembling the pen shown in the drawing, the closed end 60 of the hairpin spring 62 is pressed into the cup 56 of the plunger 52. The slots 42 and 44- are formed in the clip section 25, and the clip 30 is mounted on the clip section 25 in any suitable way. Since the guide 74 and the latch 72 are only as wide (circumferentially of the barrel) as the leg 70 is thick, the slots 40 and 42 may be made relatively narrow as compared with slots used heretofore, as will be explained hereafter. The plunger and spring 62 are inserted through the open end of the clip section 25, stem end first, until the stem 50 projects through the hole 46. The legs 65 and 70 of the hairpin spring 62 must be squeezed toward one another in order to insert them, and the leg 70 is so aligned as to permit the guide 74 to extend into the guide slot 44 and the latch 72 to project into the latch slot 42 when the spring has been pushed insufficiently far. The bearing plug 20 is then forced into the open end of the clip section 25, the cartridgeS is slid through the passage 23 in the bearing plug 20 until the end of the cartridge 3 bears against the legs of the hairpin spring at or near the mouth of the cup 56 as shown in Figures 3 and 4, and the nib section 9 of the barrel is screwed into position. When the nib section 9 is screwed onto the threaded end of the plug 20, the spring 6 will be compressed between the shoulder 7 and the annular shoulder 8.

In operation, in the posture in which the pen is found when assembled as has just been described, the ball 5 will be in extended position, thelatch shoulder 73 of latch 72, bearing against an edge of the bridge 40, restraining the movement of the cartridge to retracted position against the bias of the spring 6. In orderto permit the spring 6 to move the cartridge to retracted position; it is only necessary to push the latch72 inwardly; against the bias of the hairpin spring 62 until the latch shoulder 73 clears the edge of the bridge 40 which defines the upper end of the slot 42. Because of the slope of the cam section 75, the shoulder 73 will clear theedge of the bridge 40' before the outermost part of the latch 72 reaches the outside surface of the barrel. The bias of the spring 6 will then push the cartridge 3,-plunger 52 and hairpin spring 62 upwardly, the latch riding below the bridge 40 on the cam section 75. The length of the guide 74 and the angle of the latch leg 70' aresuch as to permit the guide 74 to remain Within the guide slot 44; In order to move the nib of the pen to extended position, it is only necessary to depress the stem 50 of the plunger 52 against the bias'of the spring-6 until the latch 72, held in line by the guide 74, snaps into the latch slot 42. When the plunger 52 is then released, the latch shoulder 73, hearing against the edge of the bridge 40 will hold the cartridge 3 in its extended position k Unlike the conventional catch mechanism, with the catch mechanism of the present invention, it is almost impossible totear ones pocket in the course of clipping the pen to it. When one attempts to insert a piece of fabric between the latch 72 and the nub 32, when the nip is extended, the smooth rounded top of the latch..72 does not tear the fabric, and the cam section 75 and nub 32 cooperate to depress the latch far enough to clear the shoulder 73, so that not only is tearing of the pocket eliminated, but the retraction of the nibis automatic when one attempts to clip the pen to hispocket when the nib is extended.

The shoulders of the conventional catch are likely to be made sharp edged in the usual'course of manufacturing. These edges tend to dig into the inside surfac'eof the clip section, which not only produces grooves in the clip section and eventually causes thecatch to become inoperative, but makes the operation of the catch st'ifi. In the catch of this invention, the rounded edge and the axial orientation of the latch 72 make the'op'eration smooth and easy, and produce almost no war on the in'sides'il'rface of the clip section. I f

The T-slot and the tab and shouldersof th'conven tional catch must be made precisely, becaus e if the stem slot is made too wide the shoulders will soon enlarge it to the point at which the cross slotwill be inefiective to hold the catch in the extended'position.-; In the device of this invention, the width of the. slots is of little, importance, since the guide will always keep .the latch aligned, and the holding of the latch is determinedonlyby the action of the latch shoulder 73 against the edgd-ofthe bridge 40. At the same time, the slots 44. and 42 maybe-made rela' tively narrow as compared with the stem and cross slots of the conventional type.

Since the force exerted on the lug of the conventional catch by the cartridge is at right angles to the line of bending of the lug, the lug tends to straighten out. The force on the latch 72, on the other hand, is in a line parallel with its line of bending which efiectively precludes any yielding of the latch 72 in response to that force.

In the conventional arrangement, the strength of the hairpin spring and of the clip must be nicely balanced. If the clip is too stifi, the lug will not move out in the cross slot. If the clip is too weak, it will not function properly as a pocket clip. With the catch of this invention, clips and springs of any desired stiffness may be used.

The fact that the clip of the conventional pen is raised by the lug makes accidental retraction of the nib commonplace. If the pen is grasped in such a way that the clip is squeezed, or if the pen is laid down on the clip, the nib will retract. With the catch of this invention, the nub of the clip forms a guard for the latch 72 so that the chances of accidental retraction when the pen is laid down are practically nil, and since the exposed part of the latch 72 is of relatively small area as compared with the clip 30, the chances of accidentally squeezing the latch 72 below the clip 30 while writing, are also negligible.

The provision of a smooth and solid surface immediately beneath the nub 32 of the clip 30, as opposed to the slotted surface below the nub of the clip of the conventional type, facilitates clipping of the pen to and its removal from a pocket.

Numerous variations in the construction of the catch of this invention within the scope of the appended claims will become apparent to those skilled in the art in the light of the foregoing disclosure. The method of mounting the hairpin spring 62 in the plunger 52, for example, may be varied in any desired fashion. The shape of the latch 72 or the guide 74 and their relative positions may be varied. The clip 30 may be made of any design, so long as it cooperates with the latch and guide in the manner described.

Thus, it can be seen that a catch mechanism is provided which is cheap and simple to manufacture and which exhibits numerous advantages over catches known heretofore.

Having thus described the invention, what is claimed and desired to be secured by Letters Patent is:

1. In a writing instrument of the character described, in which a nib is mounted to be selectively extended from and retracted into a hollow barrel, said nib being biased toward retracted position by a spring and arranged to be moved toward extended position by a plunger projecting from said barrel, said barrel having a pocket clip mounted thereon and extending axially of the barrel with a nub at a free end of said clip, and a catch mechanism mounted within said barrel, the improvement in catch mechanism which comprises a hairpin spring carried by said plunger, the legs of which spring bear opposingly against the inside wall of said barrel, a latch and a guide both extending from one of said legs in a direction toward the outside of said barrel, said barrel being provided with two, spaced, axially directed slots, the first one of said slots being positioned beneath the clip but terminating short of the nub of said clip, leaving a solid surface upon which said nub bears, the second of said slots extending from a point immediately adjacent the said nub toward the nib of said instrument, said guide extending within the first of said slots throughout the travel of said plunger between the retracted and extended position of the nib, said latch projecting through the said second slot when the nib is in extended position, and being confined within the barrel when the nib is in retracted position.

2. The catch of claim 1 wherein both the latch and the guide are integral lateral extensions of the latch leg, bent at right angles to the long axis of said leg, With their lines of bending parallel to said axis.

References Cited in the file of this patent UNITED STATES PATENTS 1,850,086 Segal Mar. 22, 1932 2,500,979 Coler-Dark Mar. 21, 1950 2,580,753 Frentzel Jan. 1, 1952 2,692,580 Kahn et al Oct. 26, 1954 2,715,888 Liguori Aug. 23, 1955 FOREIGN PATENTS 1,016,231 France Aug. 20, 1952 

